<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style type="text/css">
			.running {
				color: #BBFFAA;
			}

			.warning {
				color: yellow;
			}

			.dangering {
				color: red;
			}
		</style>
	</head>
	<body>
		<div class="running">
			系统正常运行中...
		</div>
		<script type="text/javascript">
			var div = document.getElementsByTagName('div')[0];
			setSystemStatus('dangering');
			function setSystemStatus(status) {
				div.setAttribute('class', status);
				switch (status) {
					case 'running':
						div.innerHTML = '系统正常运行中...';
						break;
					case 'warning':
						div.innerHTML = '系统运行中有告警异常';
						break;
					case 'dangering':
						div.innerHTML = '系统存在危险';
						break;
					default:
						div.innerHTML = '系统处于未知状况';
				}
			}
		</script>
	</body>
</html>
